Gauging instrument



June 24 l, 1924,.

J. A. PRESTWICH GAUGING INSTRUMENT Filed Jan. 14. 1919 2 Sheets-Sheet 1 ML M @MM U7 0;/

`hurle 24 l1924. l 1,498,750

J. A. PREs'rwlcH GAUGING INSTRUMFNIx Filed Jan. 14 1919 2 Sheets-Sheet 2 @Y Wfmw WM:

Patented .lune 24, 1924.

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GAUGING INSTRUMENT.

Application led January 14, 1919. Serial No. 271,038.

To @ZZ whom t may concern Be it known that I, JOHN ALFRED PREST- wroH, of Northumberland Park, Tottenham, London, N., England, subject of the King of Great Britain vand Ireland, have invented certain new and useful Improvements in or Relating to Gauging Instruments, of which the following is a specification.

This invention relates to gauging instruments and more especially to gauging instruments comprising a chamber adapted to be filled with a liquid and Vhaving aflexible diaphragm which carries one of the contact pieces, said chamber being provided with an indicating tube and being disposed on a bracket or frame on which is mounted the other contact piece, a micrometer screw being provided for adjusting the distance between the two contact pieces.

The object of this invention is to provide means adapted to be used in conjunction with gauges for gauging articles which cannot be placed or cannot be readily placed between the contact pieces. A

A gauging instrument made in accordance with this invention is characterized in that the ends of a pair of levers are placed between andv bear directly or indirectly on the contact pieces -f the instrument, the vother ends of the levers bearing directly or indirectly upon the work tobe gauged, these levers being pivoted on one another, forming a floating combination of levers, adapted to turn on one fixed pivot on the frame, wherein the gauging points on the work can together float or move a limited distance without aecting the contact pieces of the instrument.

Referring to the drawings filed herewith f Fig. 1 isa sectional elevation of one form of apparatusmade in accordance with this invention adapted to be held in the hand for use in measuring the internal diameter of cylinders;

Fig. 2 is a part elevation of an instrument adapted to be mounted on a table, for use` in measuring piston rings or other articles of a flexible nature; v

vFig. 3 is an elevation partly in section of an instrument adapted to be mounted on the bed of a machine for use vin measuring work in progress, for instance, work which is being stalled;

Fig. 4 is a plan View of the instrument shown in Fig. 3; l

Fig. 5 is a part sectional end view of Fig. 3. l

In Fig. l, a is an indicating tube in communication with a chamber b having a eXible diaphragm c provided witha` contact piece l vwhich forms one of the contact pieces of the gauge. The chamber b is mounted in a cylindrical casing or frame c which also carries the anvil f which forms the other contact piece of the gauge. Between the contact pieces d and f are disposed the ends g and 7L of two levers j and if: which are adapted to be pressed toward each other by aspring m coiled round a pin on the frame and pressing at one end on another pin near the end of the lever and on another pin on the frame at the other end of the said spring. One of the levers carries a pivotal point n on which the other lever bears thus forming a floating combination of levers. The end g is provided with a boss g and the end h pivots on the contact piece f. Plungers 0 and p are adapted to project slightly beyond-the cylindrical casing forming gauging points which bear on the work to be measured and the other ends of which bear on or are connected to the ends r and s of the levers j and 7c.

The casing c is extended to form a handle e0 and a casing for the indicating tube a, which is held in position by a gland e7, packing e3 and washer e4. A. split collar c5 holds a guard e6 securely to the handle e0.

Between the contact piece d and the end g of the lever is disposed a tapered distance piece t adapted to be slid into and out of position by a trigger device o through a rod to pressed by a spring to. The casing e is made slightly smaller than the cylindersto .be measured;

In use, the casing is slipped into the cylinder, the gauging points o and p bearing on the inner surface of the cylinder. `The tapered distance piece t is 'now slid to come between the contact piece d and the end g of the lever j by the trigger 'v and connecting rod w, whereupon the liquid in the chamber b is forced up the indicating tube a which enables the operator to gauge the internal diameter of the cylinder or to ascertain whether it is within the limits ofV ac- -ul'ey daalt-ed?. @lawleth@ easing' ab@ held so that its aXis is not quite parallel with the axis of the cylinder .being gauged, the combination of levers will pivot about the point'f eliminating any error which might arise from the instrument being so held.

The object ot the tapered piece t is to bring gradually the meniscus of the liquid to the index mark so as to show to a certain extent how far the object tested departs from the standard. The apparatus is irst set in connection with a standard cylinder by means of the screw f, so that when the tapered piece t is in such a position that the triggeru c is at the end of its course, the meniscus is exactly on the -index mar The apparatus is then introduced in the cylinder to be tested (the trigger c being released), and the liquid assumes a certain level. On pulling the trigger to the end of its course, the tapered piece t is now causing the liquid to rise in the tube so that its movement can be observed, and it the cylinder is of correct diameter the meniscus will stop opposite the index mark. The levers 7' and 7c may be conveniently described as floating levers moving on one of the contact pieces as a pivot.

'Referring to Fig. 2, the chamber Y) is carried by an arm e', contact piece d being mounted on a diaphragm forming a wall of the chamber. 5 is a lever pivoted at 6 on a fixed bracket secured to the trame oit' the instrument immediately below the face d. On thelever 5 is a gauging point 7. At a point 8,v on the lever 5, is pivoted another lever 9 adapted to bear on the contact piece al. On the table 1l there is provided an upstanding member 31 which is slotted in order to act its a guide for the levers 5 and 9. The lever 9 carries a gauging point 10 adapted to project above the table '11.

The levers 5 and 9 may be floating levers, that is, a combination of levers pivoted on one another and adapted to turn on one iiXed pivot similar to the floating levers described With reference to Fig. 1. The work to be gauged is placed between gauging points 7 and 10, and should the work to be gauged not lie evenly on the table 11, contacts 7 and 10 will lfollow the work and thel end 9a of the lever 9 describing an are on the pivot 6 and causing the contact piecey al to move a distance accurately corresponding with the distance between the. gauging points 7 and 10.

Referring to Fig.l 3, the chamber (Figs. 3 and 5) is carried on an arm e (Fig. 3), one Contact piece being mounted on a diaphragm which forms a wall of the chamber. @n the frame e2 is pivot'ed to the rod 28'at 29 a lever 25a on one end of which is disposed a gauging vpoint o.Y To the lever 25a isV pivotedat 27a lever 26a on oneend of which is a gaugingpoint p the other end carryng a'contact piece f which adapted to be adjusted by the screw 14. Pivote'd at 03 tothe frame c2 isa lever-15(1see' Figs.3,4 and 5) ,provided with a handle 16 and carrying a sliding distance piece 17 adapted to be slid between the contact pieces (l and rlllhe contact f of the adjusting screw 14 lies below the face of the supports or rests 18. The gauging point p on the lover 26a is adapted to bear on the under surface of the work in progress. The

- relative positions ot the arm e and frame e2 are adapted to be adjusted by pinions 20, 21, working on a rack 22 on the pillar 23 to which they are adapted to be clamped by screws 24, 25. An adjusting screw 30 bears on the lever 26a to bring the points o and 79 suitably on the work to be gauge-d.

Vihen it is desired to test the work the lever 15 is moved so as to slide the distance piece 17 between the Contact pieces l and f, whereupon the gauging points 7i of the lever 26" is brought to bear against the under side of the work, and end o ot the lever 25a is brought into contact with the top side of the work. The movement and position ot the contact piece Z will depend on the diameter of the work and consequently the operator can ascertain while the work is in progress whether it is Within the limits of accuracy desired, or what further grinding or other work must be done to bring the article being made, within the limits. On moving` the handle 16 to retract the distance piece 17, the Contact 7a on the lever 26 falls away from the work. The work can then be taken out ot the machine and placed between the supports or rests 18 and the face d which become the contact projections for checking the measurement of the Work.

What l claim as my invention, and desire to secure by Letters Patent, is:

1. In a measuring instrument having two bearing contact members, a pair of levers pivotally connected to one another intermediate their ends, one end of each ot said levers being placed between the bearing contact members and the other ends of the levers operated by the work being measured, the arrangement being such that the contact points on the work can be moved together to a limited extent without atecting the bearing contact members of the instrument.

2. In a measuring instrument having two bea-ring contact members, a pair ot levers pivotally connected to one another intermediate their ends, one end of each of said levers being placed between the bearing contact members and the other ends of the levers operated by the work being measured, the arrangement being such that the contact points on the Work can be moved together to a limited extent without affecting the bearing'contact members,and a distance piece between one of the contact members and the end ot'one of the levers.

3. A measuring instrument, comprising a chamber adapted, to be tilled with liquid, a

iieXible diaphragm constituting one wall of said chamber, a bearing contact member on said diaphragm, an indicating tube in connection with said chamber, a frame carrying said chamber, a second bearing contact member on said frame, a tapering piece for adjusting the distance between said bearing Contact members, a pair of levers pivotally connected to each other and having two ends thereof disposed between said bearing members, the other ends o'l' the levers being operated by the work being measured.

4. A measuring instrument, comprising a chamber adapted to be lled with liquid, a

"` .iieXible diaphragm constituting one wall of said chamber, a bearing contact member on said diaphragm, an indicating tube in connection with said chamber, a frame carrying said chamber, a second bearing contact member on said frame, a tapering piece for adjusting the distance between said bearing contact members, a pair of levers pivot-ally connected to each other and having two of their ends disposed between said bearing contact members, the otherv ends of the levers being operated by the work being measured, and a distance piece between one of the contact members and one end of one of the levers.

5. A measuring instrument, comprising a pair of bearing members movable with respect to the body of the instrument, a combination of levers pivotally connected to each other and forming a contact member operatively connected to both of said bearing members, indicating means, a second contact member, manually-operable means between said contact members for moving the first contact member to actuate said bearing members and to move the second contact member to actuate said indicating means.

6. A measuring instrument, comprising a pair of bearing members movable with re spect to the body of the instrument, a combination of levers pivotally connected to each other and orming'a contact member operatively connected to both of said bearing members, a diaphragm, a second contact member on the diaphragm, a movable Wedge between said contact members, manually operable means for moving said Wedge to actuate said contact members, and luid-indica-ting means operable by said diaphragm.

In testimony whereof I have signed my y name to this specification.

JOHN ALFRED PRESTWICH. 

